Hello All,
While running generic/219 fstests on a 1k blocksize on x86 box, I see
below dmesg warning msg and generic/219 fails. I haven't yet analyzed
it, but I remember I have seen such warnings before as well in my testing.
I was wondering if others have also seen it in their testing or not and
if this is any known issue?
Here it goes, 219.dmesg file.
[14459.933253] run fstests generic/219 at 2020-10-08 20:03:27
[14462.947295] EXT4-fs (vdc): mounted filesystem with ordered data mode.
Opts: acl,user_xattr,block_validity,usrquota,grpquota
[14462.992869] EXT4-fs (vdc): re-mounted. Opts: (null)
[14463.017058] EXT4-fs (vdc): re-mounted. Opts: (null)
[14463.727095] EXT4-fs (vdc): mounted filesystem with ordered data mode.
Opts: usrquota
[14463.837130] EXT4-fs (vdc): re-mounted. Opts: (null)
[14463.874293] EXT4-fs (vdc): re-mounted. Opts: (null)
[14464.149407] ======================================================
[14464.149407] WARNING: possible circular locking dependency detected
[14464.149407] 5.9.0-rc8-next-20201008 #16 Not tainted
[14464.149407] ------------------------------------------------------
[14464.149407] chown/23358 is trying to acquire lock:
[14464.149407] ffff8b9b8ff60be0 (&ei->i_data_sem){++++}-{3:3}, at:
ext4_map_blocks+0xd1/0x640
[14464.149407]
but task is already holding lock:
[14464.149407] ffff8b9b8963c208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at:
v2_write_dquot+0x2d/0xb0
[14464.149407]
which lock already depends on the new lock.
[14464.149407]
the existing dependency chain (in reverse order) is:
[14464.149407]
-> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}:
[14464.149407] down_read+0x41/0x200
[14464.149407] v2_read_dquot+0x23/0x60
[14464.149407] dquot_acquire+0x4c/0x100
[14464.149407] ext4_acquire_dquot+0x72/0xc0
[14464.149407] dqget+0x24a/0x4a0
[14464.149407] __dquot_initialize+0x1f0/0x330
[14464.149407] ext4_create+0x38/0x190
[14464.149407] lookup_open+0x4cd/0x630
[14464.149407] path_openat+0x2c4/0xa10
[14464.149407] do_filp_open+0x91/0x100
[14464.149407] do_sys_openat2+0x20d/0x2d0
[14464.149407] do_sys_open+0x44/0x80
[14464.149407] do_syscall_64+0x33/0x40
[14464.149407] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[14464.149407]
-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
[14464.149407] __mutex_lock+0xaa/0x9c0
[14464.149407] dquot_commit+0x23/0xf0
[14464.149407] ext4_write_dquot+0x78/0xb0
[14464.149407] __dquot_alloc_space+0x151/0x310
[14464.149407] ext4_mb_new_blocks+0x1f6/0x12e0
[14464.149407] ext4_ext_map_blocks+0x9c3/0x1470
[14464.149407] ext4_map_blocks+0xf4/0x640
[14464.149407] _ext4_get_block+0x90/0x110
[14464.149407] ext4_block_write_begin+0x15f/0x5a0
[14464.149407] ext4_write_begin+0x267/0x5b0
[14464.149407] generic_perform_write+0xc2/0x1e0
[14464.149407] ext4_buffered_write_iter+0x8b/0x130
[14464.149407] ext4_file_write_iter+0x6c/0x6d0
[14464.149407] new_sync_write+0x122/0x1b0
[14464.149407] vfs_write+0x1ca/0x230
[14464.149407] ksys_pwrite64+0x68/0xa0
[14464.149407] do_syscall_64+0x33/0x40
[14464.149407] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[14464.149407]
-> #0 (&ei->i_data_sem){++++}-{3:3}:
[14464.149407] __lock_acquire+0x147b/0x2830
[14464.149407] lock_acquire+0xc6/0x3a0
[14464.149407] down_write+0x40/0x110
[14464.149407] ext4_map_blocks+0xd1/0x640
[14464.149407] ext4_getblk+0x54/0x1c0
[14464.149407] ext4_bread+0x1f/0xd0
[14464.149407] ext4_quota_write+0xbf/0x280
[14464.149407] write_blk+0x35/0x70
[14464.149407] get_free_dqblk+0x42/0xa0
[14464.149407] do_insert_tree+0x1d6/0x480
[14464.149407] do_insert_tree+0x464/0x480
[14464.149407] do_insert_tree+0x218/0x480
[14464.149407] do_insert_tree+0x218/0x480
[14464.149407] qtree_write_dquot+0x79/0x1b0
[14464.149407] v2_write_dquot+0x52/0xb0
[14464.149407] dquot_acquire+0x8e/0x100
[14464.149407] ext4_acquire_dquot+0x72/0xc0
[14464.149407] dqget+0x24a/0x4a0
[14464.149407] dquot_transfer+0xfe/0x140
[14464.149407] ext4_setattr+0x134/0x9c0
[14464.149407] notify_change+0x34b/0x490
[14464.149407] chown_common+0x96/0x150
[14464.149407] do_fchownat+0x8d/0xe0
[14464.149407] __x64_sys_fchownat+0x21/0x30
[14464.149407] do_syscall_64+0x33/0x40
[14464.149407] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[14464.149407]
other info that might help us debug this:
[14464.149407] Chain exists of:
&ei->i_data_sem --> &dquot->dq_lock -->
&s->s_dquot.dqio_sem
[14464.149407] Possible unsafe locking scenario:
[14464.149407] CPU0 CPU1
[14464.149407] ---- ----
[14464.149407] lock(&s->s_dquot.dqio_sem);
[14464.149407] lock(&dquot->dq_lock);
[14464.149407] lock(&s->s_dquot.dqio_sem);
[14464.149407] lock(&ei->i_data_sem);
[14464.149407]
*** DEADLOCK ***
[14464.149407] 6 locks held by chown/23358:
[14464.149407] #0: ffff8b9b8963c480 (sb_writers#3){++++}-{0:0}, at:
mnt_want_write+0x20/0x50
[14464.149407] #1: ffff8b9b8ff64bc8
(&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: chown_common+0x85/0x150
[14464.149407] #2: ffff8b9b670c48d8 (jbd2_handle){++++}-{0:0}, at:
start_this_handle+0x1ad/0x690
[14464.149407] #3: ffff8b9b8ff648d0 (&ei->xattr_sem){++++}-{3:3}, at:
ext4_setattr+0x129/0x9c0
[14464.149407] #4: ffff8b9b1313f5f0 (&dquot->dq_lock){+.+.}-{3:3}, at:
dquot_acquire+0x23/0x100
[14464.149407] #5: ffff8b9b8963c208 (&s->s_dquot.dqio_sem){++++}-{3:3},
at: v2_write_dquot+0x2d/0xb0
[14464.149407]
stack backtrace:
[14464.149407] CPU: 5 PID: 23358 Comm: chown Not tainted
5.9.0-rc8-next-20201008 #16
[14464.149407] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.13.0-1ubuntu1 04/01/2014
[14464.149407] Call Trace:
[14464.149407] dump_stack+0x77/0x97
[14464.149407] check_noncircular+0x132/0x150
[14464.149407] ? sched_clock_local+0x12/0x80
[14464.149407] __lock_acquire+0x147b/0x2830
[14464.149407] lock_acquire+0xc6/0x3a0
[14464.149407] ? ext4_map_blocks+0xd1/0x640
[14464.149407] down_write+0x40/0x110
[14464.149407] ? ext4_map_blocks+0xd1/0x640
[14464.149407] ext4_map_blocks+0xd1/0x640
[14464.149407] ? sched_clock_local+0x12/0x80
[14464.149407] ext4_getblk+0x54/0x1c0
[14464.149407] ext4_bread+0x1f/0xd0
[14464.149407] ext4_quota_write+0xbf/0x280
[14464.149407] write_blk+0x35/0x70
[14464.149407] get_free_dqblk+0x42/0xa0
[14464.149407] do_insert_tree+0x1d6/0x480
[14464.149407] ? ext4_quota_read+0x9d/0x110
[14464.149407] do_insert_tree+0x464/0x480
[14464.149407] ? ext4_quota_read+0x9d/0x110
[14464.149407] do_insert_tree+0x218/0x480
[14464.149407] ? ext4_quota_read+0x9d/0x110
[14464.149407] do_insert_tree+0x218/0x480
[14464.149407] ? __kmalloc+0x319/0x350
[14464.149407] qtree_write_dquot+0x79/0x1b0
[14464.149407] v2_write_dquot+0x52/0xb0
[14464.149407] dquot_acquire+0x8e/0x100
[14464.149407] ext4_acquire_dquot+0x72/0xc0
[14464.149407] dqget+0x24a/0x4a0
[14464.149407] dquot_transfer+0xfe/0x140
[14464.149407] ext4_setattr+0x134/0x9c0
[14464.149407] notify_change+0x34b/0x490
[14464.149407] ? chown_common+0x96/0x150
[14464.149407] chown_common+0x96/0x150
[14464.149407] ? preempt_count_add+0x49/0xa0
[14464.149407] do_fchownat+0x8d/0xe0
[14464.149407] __x64_sys_fchownat+0x21/0x30
[14464.149407] do_syscall_64+0x33/0x40
[14464.149407] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[14464.149407] RIP: 0033:0x7efd3d2666ca
[14464.149407] Code: 48 8b 0d c9 f7 0c 00 f7 d8 64 89 01 48 83 c8 ff c3
66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 04 01 00 00 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 96 f7 0c 00 f7 d8 64 89 01 48
[14464.149407] RSP: 002b:00007ffdbe6ae418 EFLAGS: 00000206 ORIG_RAX:
0000000000000104
[14464.149407] RAX: ffffffffffffffda RBX: 00007ffdbe6ae650 RCX:
00007efd3d2666ca
[14464.149407] RDX: 0000000000007ab7 RSI: 00005598d654ef60 RDI:
00000000ffffff9c
[14464.149407] RBP: 00000000ffffff9c R08: 0000000000000000 R09:
00000000ffffffff
[14464.149407] R10: 00000000ffffffff R11: 0000000000000206 R12:
00005598d654e1f0
[14464.149407] R13: 00005598d654e268 R14: 0000000000007ab7 R15:
00000000ffffffff
[14465.070206] EXT4-fs (vdc): mounted filesystem with ordered data mode.
Opts: grpquota
[14465.165678] EXT4-fs (vdc): re-mounted. Opts: (null)
[14465.201132] EXT4-fs (vdc): re-mounted. Opts: (null)
